Master cylinders



Jan. l, 1946. M. L. MAs'i'ELLl-:R

MASTER CYLINDERS 3 Sheets-Sheet 1 Filed June 14, 1945 am mm SNA* Jan. l, 1946. M, MAsTELLER I MASTER c YLINDERs Filed June 14, 1943 5 Sheets-Sheet 2 Jan. l, 1946.

Filed June 14, 1945 M. L. MASTELLER MASTER CYLINDERS 5 Sheets-Sheet 3 Z7 53 c 27 ,r B 27 H A Il 43 ad al 56 v 22' g3 54- 25 24- o o a: @o 3 55 a5 5c as an f 3B 456A :a9 g Je 3945 37 36 o sa 59 A l 37 4a v //VV/V70/?.

Patented Jan. 1, 1946 UNITED STATES .QPATENT OFFICE MASTER CYLINDERS Malcolm L.,Masteller, lVIiami, Fla.

Application June 14, 1943, Serial No. 490,939

(ci. so-54.5)

Claims.

This invention relates to improvements in master cylinders and the object of the improvement is to provide a simple and practical multiple master cylinder device for building up a predetermined relative pressure in plural fluid pressure systems, as for the separate braking of diierent wheels.

I attain this object by mechanism illustrated in the accompanying drawings to which I now refer:

Figure l is a side elevation of dual master cylinders and their operating means, one cylinder being broken away and shown in section, according to the invention.

Figure 2 is a side elevation of dual master cylinders in modified form, both cylinders being partly broken away and shown in section, according to the invention.

Figure 3 is a vertical cross section taken on the line 3-3 of Figure 1.

Figure 4 is a horizontal section taken on the line 4-4 of Figure l.

Figure 5 is a side elevation of triple masterl cylinders according to the invention.

Like numerals refer to like parts throughout the illustrations.

The device of Figure l comprises master cylinder A conventionally mounted in fixed :position and reciprocating master cylinder B. Each of these master cylinders comprises casing II, compression chamber I2, compressor piston I3 having an annular recess forming compartment I4 between said piston and said casing, with its primary packing cup I5 and secondary packing cup I5, compression spring I1 urging said piston toward end washer I8 which is held against a shoulder in said casing II by retaining ring I9 which in turn is held in an annular groove in casing l I by its own resilience, running stop member 28, forward end closure 2| with its projection 2l forming a xed stop, gasket 22, fitting 23 adapted for connecting the conventional conduit 24 or the exible conduit 24 of the respective fluid pressure systems, the conventional double acting check-Valve 25, supply chamber 26 with its vented closure member 21, and all of the conventional passages 28, 29, 30, 3l and 32, also bosses 33-33 by means of which it is mounted on the vehicle chassis member 34; master cylinder A in Xed position supported by bolts 35 and their nuts 36 together with spacing bracket 31; master cylinder B so as to have reciprocal motion in relation to master cylinder A, swinging here on rockers 38 to which it is pivoted by means of pins 39-39' with washers 40 and cotter pins 4|.

Each of said rockers 38 is pivoted on a pin 42 IIS which is supported (Figs. 3 and 4) by bracket 31 which is aliiXed to the chassis member 34Aby means of bolts 44 and nuts 45, said rockers being held on pins 42 by washers 46 and cotter pins 41. Operating rod 48-48 with its `conventional adjusting means 49 is also pivoted on pin 39' and on pin 50 of operating pedal lever5I `which is fulcrumed at 52 and is provided. with extension spring 53 adapted to support it normally resting against the conventional adjustable stop 54. Between the two master cylinders is the common piston rod 55 adapted to operate both pistons, and boot assembly E56- 56CV The device of Figure 2 is the same as that of Figure -l excepting that. master cylinder B is turned `around and master cylinder A, whose casing is otherwise designated as I I', has its cylinder, and compressor piston I3' and its packing cups, of lesser diameter than those of master cylinder B. as shown by dimension lines Y-Z of which Z is the shorter, said differential resulting in building up a higher `relative pressure in master cylinder A and its respective iuid'pressure system. Also in this device operating rod 48 is adjustably attached to piston rod 51 of master cylinder B, and operating rod 58 of master cylinder A is pivoted to pin 39. In this device there is also provided the extension spring 59 and adjustable stop 60, the latter being associatedwith bracket 31 and being necessary to a complete release between piston rod 51 and its piston I3.

With dual hydraulic systems it' is primarily intended that one of them be associated with the brakes of the front wheels of a vehicle and the other one with the brakes of the rear wheels. Should there be three pairs of braking wheels, either on the vehicle itself or on vehicle and trailer, one pair can be associated with one hydraulic system and two pairs with the other one, or there may be three master cylinders, two reciprocating and one preferably in fixed position. This device is illustrated in Figure 5, it vcomprising master cylinder A conventionally mounted in iixed position, and dual reciprocating master cylinders B and C joined together by means of adjustable connecting rod 6I so that they reciprocate as one. Extension spring 59 and adjustable stop 66 are used here, and master cylinder B is here illustrated as of type II', all as described in the preceding paragraph.

In operation (Fig. l) when pedal lever 5I is thrust forward, master cylinder B moves forward and its approach to master cylinder A causes piston rod 55 to move both pistons forward in their respective cylinders, thereby discharging liquid from them into lthe conduits 24-24 of the respective uid pressure systems, and an equalized pressure is built up in them.

In operation (Fig. 2) when pedal lever 5l is thrust forward, piston I3 of master cylinder B is likewise thrust forward and as iluid pressure is built up in said master cylinder B, this in turn moves said master cylinder forward, together with operatingrod 58 and piston I 3 of master cylinder A, with the same result as described above in regard to the device of Figure 1', excepting that a predetermined variation in the pressures of the respective systems will be maintained.

In operation (Fig. 5). a different combination of the same elements as above described in regard to Figures` l and"2"fand no further description is thoughtwtobenecessary:

excepting to state that operating power and motion is here transmitted from master cyli'nd'erftot master cylinder by the newelement here introduced, viz: adjustable connectingl rod 6l.

Inany of' these combinations.y the pressure' applied. by the. operator upon the rst compressor willsi'multaneously and .withpredeterminedratios become'effctive upon the balance of them without any, additional effort',. an Without any greater movement than would be' required to perform the same braking with a single master cylinder.

`Ii` there is noiluid' pressure in a given system, the respective piston l3-I3"`will advance the full length of' its range" when' its running stopv member 20 willengageilxedstopZ'l thereby preserving. the integrity of the rest", the. combined ranges o'f the'se'veral pistons' beihg vin no case' greater than that of' operating rod 48' as1 limited by the maximum r'noven'ie'ntof pedali BZ to the floor bard:

Whatl claimist l; Inplural" masterV cylinders f'orA controlling plural uid: pressure` systems, including means for protecting the integrity' of one'y system in case of failureof another; the combination of acylinder,

This device isf merelyhaving an open end and a closed end, mounted in xed position, a second cylinder having an open end and a closed end and adapted for longitudinal reciprocal motion in relation to said'frst cylinder, a piston slidable in said first cylinder and a piston slidable in said second cylinder` and means including the reciprocal motion of said second cylinder for simultaneously advancing said pistons intheir respective cylinders.

2; The device of claim 1` in which there is a variation in the diameters of the respective cylinders.

3. Plural master cylinders for controlling plural rluidlpressure systems, comprising a cylinder having an open end and a closed end, a second cylinder'having an open end and a closed end and adapted forxlongitudinal reciprocal motion in r'elation to said first cylinder, a piston slidable in said rstcylinder, a piston slidable in said second cylinder, a. common meansv operableupon both of saidplstons forV simultaneously advancing them intheir respective cylindersrwhenA said reciprocatingv cylinderv is thrust. upon said common means, and means for effecting saidthrust.

4.4 The device4 of claim 3, in which said com,- mon means is a piston rod common tov both pistons.

5. Dual. master cylindersI including a master cylinder adapted forreciprocal motion in relationto. said other. master cylinder, each comprising, acylinder having, a, closed. end and an open end, a piston slidable within one ofsaid cylinders anda piston rod for its. operation, a piston slidable Within the other of. said. cylinders anda piston rod for its operatiomand. means for operating said rods including a l'ever operable upon the rod in the reciprocatingV master cylinder causing it to advance and means connecting, saidreciprocating master cylinder to` said, other piston rod to operate saidother piston.

MALCOLM, MASTELLER. 

